The Obama administration’s income-driven repayment program will cost more than twice as much as the Department of Education initially thought it would, according to a new report from the Government Accountability Office.

From its rollout in 2009, during the depths of the recession, the optional income-driven repayment (IDR) program intended to help federal student loan borrowers avoid default. IDR allows borrowers to pay back their loans only once they can afford to, at which time they will have fewer years to complete repayment.